A conventional passenger seat for an aircraft comprises a back-rest and a seat-pan that are supported off the floor of the vehicle by means of a suitable supporting structure that is anchored to a pair of seat tracks in the floor. The seat defines a notional longitudinal seat axis, as viewed from the perspective of a passenger using the seat, and a plurality of such seats are adapted to be arranged in rows in a passenger accommodation cabin within the fuselage of an aircraft, each row extending transversely across the cabin, one behind another, with the notional seat axis of each seat substantially aligned with the longitudinal axis of the fuselage such that each seat faces forwards. Usually, the back-rest of the seat is capable of reclining from an upright position to a reclined position for the comfort of a passenger using the seat during the course of a flight. Some prior art passenger seats, particularly seats for use in business-class and first-class of sections of aircraft, where the pitch between adjacent rows of seats is greater than in an economy-class cabin, also comprise a leg-rest which is hinged to the front of the seat-pan and is capable of movement between a lowered or stowed position, in which the leg-rest depends from the seat-pan generally vertically towards the floor, and a raised or deployed position in which the leg-rest extends forwardly of the seat-pan to bear the passenger's legs off the floor. Thus, it is possible with conventional aircraft passenger seats to obtain a fair degree of comfort by reclining the back-rest and elevating the leg-rest, when fitted.
Whilst the above-described arrangement of conventional aircraft passenger-seats is generally satisfactory for short-haul flights having a duration of up to three or four hours, it is not satisfactory for use on longer flights during which passengers typically wish to go to sleep. Even in the reclined position described above, a passenger using the seat remains in a general sitting position. Many passengers find it difficult to sleep properly, if at all, when sitting. In recent years there has been a significant increase in the number of passengers who regularly make long-haul flights, and there has been a trend in the art to devise passenger seats which allow passengers to adopt further reclined positions during the course of a flight to facilitate sleeping. This is particularly important for passengers who travel for business purposes for whom it is desirable that they arrive at their destinations feeling refreshed and alert.
One possibility that has been disclosed in the art for increasing the degree to which an aircraft passenger seat can be reclined comprehends simply increasing the extent to which the back-rest can be reclined backwards and the leg-rest elevated. In the extreme, it is possible to form a substantially flat bed using such a technique in which the back-rest is reclined and the leg-rest raised, each to such an extent that they are disposed substantially co-planarly with the seat-pan and each other. A disadvantage of such a system is that the pitch between adjacent rows of seats must be increased substantially to accommodate the full height of a passenger. Whilst this is sometimes possible in the first-class area of an aircraft cabin, it is generally uneconomic for a business-class cabin. Furthermore, whilst it is possible to form a generally flat surface which is disposed substantially horizontally, the surface is still not ideal, because the foam or other padding on the seat is generally sculptured for use as a seat, whereas for a bed, it is desirable to have a substantially flat surface.
GB 2326824 A discloses a seating unit for a first class aircraft cabin comprising a secondary seat positioned to face a primary seat, the secondary seat having a seating portion positioned to cooperate with a leg-rest of the primary seat to form a continuous, flat sleeping surface when the back-rest of the primary seat is reclined to a horizontal position. The seating unit defines a notional, longitudinal seat axis, and a plurality of such seating units may be arranged within the cabin side-by-side in a longitudinally offset relation with respect to the longitudinal axis of each seat, with each seating unit being oriented at an acute angle to the longitudinal axis of the aircraft fuselage, so as to define a generally triangular or trapezoidal space to the front or rear of each seating unit (according to whether the seating units face outwards or inwards relative to the cabin). The space is used to accommodate a counter-top to one side of an adjacent seating unit and optionally a cupboard or other storage space. The seating unit of GB 2326824 A has the advantage that by incorporating an additional, secondary seat in the flat sleeping surface together with back-rest, seating portion and leg-rest of the primary seat, it is possible to form a long sleeping surface which is able to accommodate comfortably passengers having a height of greater than 6 ft (1.83 m). However, the seating unit of GB 2326824 A represents an even greater overhead in turns of cabin space than the conventional system described above and, moreover, still suffers from the disadvantage that the seat cushioning is designed principally for use as a seat and not a bed. A disadvantage of the seat of GB 2326824 A is that it occupies a very large floor area within the cabin and, in view of its overall length, the seating unit of GB 2326824 A is wholly unsuitable for use in a business class section of an aircraft.
WO 00/21831 A2 discloses a seating unit which can be converted into a bed for use principally in a business-class section of aircraft cabin. The seating unit of WO 00/21831 A2 comprises a pair of seats facing in opposite directions, each seat comprising a seating space for the seated body of an occupant and an extension space in which the legs of an occupant may be placed. The seats are positioned each side of a notional dividing axis with the seating space of one extending over the axis into the extension space of the other. When installed in an aircraft cabin, one of the seats faces substantially forwards and the other faces substantially aft. Each seat of the. seating unit of WO 00/21831 A2 comprises a primary seat that is substantially the same as the primary seat of GB 2326824 A described above, but without a leg-rest, and a secondary unit spaced forwardly of the primary seat. Each seat thus comprises a primary seat having a reclinable back-rest and seat-pan and a secondary unit comprising an elevated pad which serves as a foot-rest. The primary seat can be reclined such that as the back-rest is reclined, the seat-pan moves forwardly to meet the secondary unit to form a continuous surface therewith which serves as a sleeping surface for a passenger. As with GB 2326824 A, the seating unit of WO 00/21831 A2 therefore has the advantage of providing a substantially horizontal sleeping surface for a passenger during long-haul flights. However, the seating unit of WO 00/21831 A2 is still extravagant in terms of the space available within a typical business-class cabin and also suffers from the disadvantage that when configured as a bed, each seat is unable to accommodate comfortably tall passengers. As with the other prior art seats described above, each of the seats of the seating unit of WO 00/21831 A2 also suffers from the disadvantage that the seat cushioning is not specifically designed for use as a bed surface, but is contoured for use principally as a seating surface.
Another attribute of a passenger seat for use in a first-class aircraft cabin is a generous seat width. A further disadvantage associated with the seating unit of WO 00/21831 A2 is that in order to accommodate a maximal head count within a business class cabin, the seat width is reduced, which many passengers find to be uncomfortable. Whilst the seating unit of WO 00/21831 A2 has the undeniable benefit of providing a substantially flat sleeping surface for a passenger in-flight, its overall dimensions are such that passengers of above average height and/or weight find the accommodation somewhat cramped. Furthermore, privacy screens are provided between adjacent seating units which, in combination with the total number of seating units provided in the limited space afforded by a business class cabin, result in the cabin as a whole having a somewhat crowded appearance.
FR 987559 A discloses a seating installation for public transport vehicles such as motor cars, auto buses and the like comprising a row of seats, each seat comprising a supporting structure for supporting the seat off the floor of a vehicle, a seat-pan and a back-rest. Said row defines an aisle between two adjacent seats. The seat-pan of one of the seats adjacent the aisle can be removed and slung in an inverted orientation between the supporting structures of the two seats adjoining the aisle to form an additional seat in the aisle. The back-rest of the one seat can then be rocked forwards into the space formerly occupied by the seat-pan to provide a replacement seat-pan for the one seat. The back-rest of the one seat thus has front and rear surfaces which can both serve as part of a seat. Optionally the entire row of seats could support a mattress to form a couchette. However, the installation of FR 987559 A is not suitable for use on a passenger aircraft where the aisles must be kept unobstructed at all times and, furthermore, a plurality of adjacent seats are used to provide support for a single couchette. Thus the installation of FR 987559 A is not able to provide one couchette per seat.
JP 5-13838 A discloses a seating system for vehicles such as buses and trains comprising a plurality of seats. Each seat comprises a seat-pan and a back-rest that can rock between an upright position and a reclined position, and the seats are positioned within a cabin at an angle with respect to a centre-line of the cabin and face outwardly to define a generally triangular space between each seat and a wall of the cabin. Said space accommodates a box comprising a foot-rest for an adjacent seat.
FR 647809 A discloses a seating system for a sleeping car in which a plurality of seats are arranged at an angle to the longitudinal axis of the sleeping car, facing inwardly to define a generally triangular space to the rear of each seat which is used to accommodate a small table for an adjacent seat.